On Saturday, Westlake Village Inn Hotel in Westlake Village Calif., buzzed with excitement following Tiger Wood's 14th Annual World Challenge Golf Tournament.

Northern Ireland's Graeme McDowell took home top honors, winning his second World Challenge. But the real celebration was happening at Bogies, the hotel's lakeside bar and lounge, which held the closing party for the tournament.

At Bogies, Tiger Woods stepped out dressed in jeans and beige sweater.

"He was all smiles as he danced the night away," an onlooker tells PEOPLE. "At one point, he was surrounded by a group of six women on the club's dance floor."

The man of the hour, Woods requested songs alongside the deejay as the party went on.
– Jennifer Garcia

Anna Wintour, Michael Kors, Joan Collins and Tony Danza were also there to enjoy passed items from Chef Michael Lomonaco including roasted sliced filet mignon with cabernet and shallot sauce, porcini mushroom ravioli with white truffle cream and bite-sized desserts including New York state apple pie, cream puffs and mini ice cream sandwiches.

But the most delicious part of the evening was when Jackman – accompanied by a pianist – serenaded Seyfried with "Happy Birthday" while she stood on top of the grand piano bench in the center of the dining room.

Emily VanCamp and her costar – and off-screen boyfriend – Josh Bowman attended the Mending Kids International Four Kings & An Ace Charity Poker event at West Hollywood hotspot The London on Saturday.

"Emily looked stunning in a nude and black cocktail dress while Josh complimented the outfit with a chic suit and tie," an onlooker at the event, sponsored by El Cartel Tequila, tells PEOPLE. "After laughing over their popcorn, the pair headed to one of the VIP rooms where the celebrity poker tournament was underway."

At the celebrity poker tournament – where player tickets were $10,000 a person! – Robert Downey Jr., Jodie Foster, Sean Penn, Mel Gibson and Gene Simmons played for a good cause.

Although she made a brief appearance, while in attendance, Holmes – who made her Broadway debut in 2008 in a revival of Arthur Miller's All My Sons – was in "good spirits" and spent a lot of time with costar Judy Greer, the source adds.

Rachel Zoe and husband Rodger Berman stepped out to celebrate the stylist-turned-designer's "Major Must Haves" from Jockey at the Sunset Tower in West Hollywood on Wednesday.

"Rachel and Rodger arrived hand in hand. They mingled together and when Rachel had business to tend to, Rodger still enjoyed himself, chatting with guests and their team," an onlooker tells PEOPLE. "He had a proud eye on Rachel."

The parents to Skyler, 19 months, "worked the room like partners," the source says.

When it came time for Zoe to address the crowd, Berman stood front row and laughed at all her jokes as he sipped on a dirty Martini.